JOAO COUTINHO FERREIRA

JOAO COUTINHO FERREIRA

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Purification of lithium hydroxide by ion-exchange processes for application in nuclear reactors
2021 - GIMENEZ, MAISE P.; OTOMO, JULIANA I.; FERREIRA, JOAO C.; BERGAMASCHI, VANDERLEI; BUSTILLOS, OSCAR V.
Thorium and lithium in Brazil
2019 - OLIVEIRA, GLAUCIA A.C. de; LAINETTI, PAULO E.O.; BUSTILLOS, JOSE O.W.V.; PIRANI, DEBORA A.; BERGAMASCHI, VANDERLEI S.; FERREIRA, JOAO C.; SENEDA, JOSE A.
Brazil has one of the largest reserves of thorium in the world, including rare earth minerals. It has developed a great program in the field of nuclear technology for decades, including facilities to produced oxides to microspheres and thorium nitrates. Nowadays, with the current climate change, it is necessary to reduce greenhouse gas emissions, one of this way is exploring the advent of IV Generation reactors, molten salt reactors, that using Thorium and Lithium. Thorium's technology is promising and has been awaiting the return of one nuclear policy that incorporates its relevance to the necessary levels, since countries like the BRICS (without Brazil) have been doing so for years. Brazil has also been developing studies on the purification of lithium, and this one associated to thorium, are the raw material of the molten salt reactors. This paper presents a summary of the thorium and lithium technology that the country already has, and its perspectives to the future.
Purification of lithium carbonate by ion-exchange processes for application in nuclear reactors
2019 - ANDRADE, MARIANA N.; OLIVEIRA, GLAUCIA A.C.; PIRANI, DEBORA A.; COUTINHO, JOAO F.; BERGAMASCHI, VANDERLEI S.; SENEDA, JOSE A.; BUSTILLOS, JOSE O.V.
Lithium Compounds have applications in strategic areas for intern consumption of a country as well as international commerce. In nuclear industry, the lithium is used for the cooling of PWR reactors as a pH stabilizer. Based on this assumption, the generation of knowledge to master the processing cycle of these compounds is essential. The high degree of purity of lithium compounds is determinant to have success in these applications. Lithium hydroxide LiOH and lithium carbonate Li2CO3 are the main forms in which lithium is used industrially. To improve the quality of the starting product, purifying process were used until obtaining an adequate purity level of raw material (> 99%). The present work aims to make feasible a purification of Li2CO3 through ion-exchange chromatography from a 98.5% purity compound. The impurities present in higher content are sodium and calcium. To separate these two elements from lithium or at least to lower their concentrations, a column with cationic resin was used to fix lithium. The determination of lithium, sodium and calcium contents in the solutions was performed by inductively coupled plasma optical emission spectrometry, ICP-OES. The experiments performed to evaluate the best lithium purification condition were based on the variation of the main operational parameters: pH, flow and elution solution. The results indicate increased purity from the application of ion exchange operations obtaining a suitable condition for nuclear uses.
Transformacao via peroxido de um hidroxido bruto de torio em nitrato para camisas de lampiao
2002 - FREITAS, A.A.; CARVALHO, F.M.S.; FERREIRA, J.C.; ABRAO, A.
Uranium recovery from waste of the nuclear fuel cycle plants at IPEN-CNEN/SP
2011 - FREITAS, ANTONIO A.; FERREIRA, JOAO C.; ZINI, JOSIANE; SCAPIN, MARCOS A.; CARVALHO, FATIMA M.S. de
Transformação via peróxido de um hidróxido bruto de tório em nitrato para camisas de lampião
2002 - FREITAS, A.A.; CARVALHO, F.M.S.; FERREIRA, J.C.; ABRAO, A.
Apresenta-se neste trabalho um processo alternativo para a recuperação e purificação de tório partindo-se de um hidróxido bruto como precursor, cuja composição média é 60,1% em óxido de tório (ThO2), 18,6% em óxidos de terra raras (TR2O3) e impurezas comuns como silício, ferro, titânio, chumbo, sódio e outros. Este material foi produzido industrialmente da monazita processada no Brasil e estocado há alguns anos. Este hidróxido de tório bruto é tratado com ácido nítrico a quente e, depois da digestão e adição de floculante, é filtrado para a separação da fração insolúvel. Usando-se esta solução de nitrato de tório, precipitou-se o peróxido após o ajuste do pH e a adição controlada de peróxido de hidrogênio. O peróxido de tório assim obtido foi dissolvido com ácido nítrico e o nitrato de tório resultante tem qualidade para ser usado na fabricação de camisas para lampião a gás. Os elementos das terras raras são recuperados totalmente no filtrado do peróxido de tório.